Optimal eigen-beamforming combined with orthogonal STBC and TCM in correlation fading channels

This paper develops a novel system which combines the two dimensional (2D) eigen-beamforming (EBF) with orthogonal space-time block code (O-STBC) and trellis coded modulation (TCM) for transmit correlation fading channels. The corresponding statistic error event probability analytical expressions, power load algorithms and TCM design criteria are achieved respectively for two cases: with or without interleaver. The former achieves build-in-time diversity besides beamforming diversity and code gain from product-sum distance, and which requires channel correlations to keep constant over the interleaving length. The latter obtains beamforming diversity and code gain from free distance. The power allocation algorithms show a new feature that relates to code distance other than minimum Euclidian distance among constellation points, which can lows the threshold of achieving beamforming diversity. The conventional ID beamforming is proved to be a special case. Furthermore, the analysis and simulation results show the proposed system can offer good performance with low decode complexity and has no space-time code rate lost with random number of transmit antennas.